EXPERIMENTAL ASSESSMENT OF TOXIC EFFECTS OF TROTYL (TNT) ON SOIL MICROFLORA

An experimental assessment of the hazard of trotyl content in the soil has been carried out according to one of the most significant sanitary indicators of harm - the microbiocenosis. E. coli, micromycetes, actinomycetes and saprofitny bacteria grown up in the specific to each microflora medium were used as test organisms. It was found that the content of the toxicant in the soil at the levels of 20.0 and 10.0 mg/kg during the experiment revealed a significant growth of E. coli (up to 458.87 % relative to the control) indicating the inhibition of the process of self-purification of the soil. In addition, TNT in these concentrations contributed to a significant growth of micromycete colonies (up to 200.00%) indicating its accumulation in the soil, where fungi act as indicators (toxin accumulators). At the same time the substance at the level of 20.0 mg/kg caused inhibition of vital activity of actinomycetes reaching 50.27 %. The number of colonies of saprophytic microflora also significantly decreased in the soil mixture with the content of the chemical at the levels of 20.0 and 10.0 mg/kg. According to this type of general health hazard indicator the concentration of TNT – 10.0 mg/kg has been accepted as a threshold, and the value of 2.0 mg/kg – as inactive. The data obtained are taken into account in the subsequent development of the hygienic standard for this explosive compound.

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Potential Public Health Significance of Non-Escherichia coli Coliforms in Food

Journal of Food Protection ◽

10.4315/0362-028x-42.2.161 ◽

1979 ◽

Vol 42 (2) ◽

pp. 161-163 ◽

Cited By ~ 10

Author(s):

ROBERT M. TWEDT ◽

BRENDA K. BOUTIN

Keyword(s):

Public Health ◽

Escherichia Coli ◽

Diarrheal Disease ◽

Health Hazard ◽

High Yield ◽

Potential Health ◽

E Coli ◽

Potential Health Hazard ◽

Health Significance

Several coliform species other than Escherichia coli are often associated with and possibly responsible for acute and chronic diarrheal disease. Recent evidence suggests that non-Escherichia coli coliforms may be capable of colonizing the human intestine and producing enterotoxin(s) in high-yield. Whether these organisms are newly capable of causing disease because of infestation with extrachromosomal factors mediating pathogenicity or simply because of inherent pathogenic capabilities that have gone unrecognized, they pose a potential health hazard. Food, medical, and public health microbiologists should be aware that the non-E. coli coliforms contaminating foods may be potential enteropathogens. This possibility may make determination of their pathogenic capabilities even more important than identification of their taxonomic characteristics.

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Survival of cryptosporidium parvum, escherichia coli, faecal enterococci and clostridium perfringens in river water: influence of temperature and autochthonous microorganisms

Water Science & Technology ◽

10.2166/wst.1997.0742 ◽

1997 ◽

Vol 35 (11-12) ◽

pp. 249-252 ◽

Cited By ~ 61

Author(s):

G. J. Medema ◽

M. Bahar ◽

F. M. Schets

Keyword(s):

Surface Water ◽

River Water ◽

Cryptosporidium Parvum ◽

Health Hazard ◽

Influence Of Temperature ◽

E Coli ◽

Untreated Water ◽

Time Required ◽

Micro Organisms

Oocysts of Cryptosporidium parvum can survive for several months in surface water, one of the main factors determining their success in environmental transmission and thus their health hazard via water. Several factors in the environment, e.g. temperature, presence of predators and exo-enzymes will probably influence oocyst survival. The high persistence of oocysts may also limit the value of traditional faecal indicator bacteria. The aim of this study was to determine the rate at which C parvum oocysts, E coli, faecal enterococci and C perfringens spores die in surface water and the influence of temperature and the presence of autochthonous (micro)organisms on the die-off rate. Microcosms with autoclaved river water were inoculated with the organisms. Microcosms with untreated river water were inoculated with concentrated primary effluent containing the bacteria and with C parvum oocysts. Microcosms were incubated at 5°C or 15°C at 100rpm. Viability of oocysts was monitored by in vitro excystation and dye-exclusion; viability of the bacteria was determined on appropriate selective media. When pseudo first-order die-off kinetics were assumed, the die-off rate of oocysts at 5°C was 0.010 log10/d and at 15°C, 0.006–0.024 log10/d. These rates underestimate die-off since oocyst disintegration was not accounted for. Incubation in autoclaved or untreated water did influence the die-off rate of oocysts at 15°C but not at 5°C. The die-off rate of E coli and enterococci was faster in the non-sterile river water than in autoclaved water at both temperatures. At 15°C, E coli (and possibly E faecium) even multiplied in autoclaved water. In untreated river water, the die-off of E coli and enterococci was approximately 10x faster than die-off of oocysts but die-off rates of C perfringens were lower than those of oocysts. As for oocysts, die-off of the bacteria and spores was faster at 15°C than at 5°C. Oocysts are very persistent in river water: the time required for a 10x reduction in viability being 40–160d at 15°C and 100d at 5°C. Biological/biochemical activity influenced oocyst survival at 15°C and survival of both vegetative bacteria at 5 and 15°C. The rapid die-off of E coli and enterococci makes them less suitable as indicators of oocyst presence in water. As C perfringens survived longer in untreated river water than oocysts, it may prove useful as an indicator of the presence of C parvum.

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Effect of Gamma Irradiation on the Survival of Pathogens in Kwamegi, a Traditional Korean Semidried Seafood

Journal of Food Protection ◽

10.4315/0362-028x-66.11.2093 ◽

2003 ◽

Vol 66 (11) ◽

pp. 2093-2096 ◽

Cited By ~ 25

Author(s):

S. P. CHAWLA ◽

D. H. KIM ◽

C. JO ◽

J. W. LEE ◽

H. P. SONG ◽

...

Keyword(s):

Low Temperature ◽

Salmonella Typhimurium ◽

Water Activity ◽

Pathogenic Bacteria ◽

Radiation Sensitivity ◽

E Coli ◽

Public Health Significance ◽

Irradiation Treatment ◽

Test Organisms ◽

Health Significance

Kwamegi (semidried raw Pacific saury) is traditional seafood available in Korea. It has water activity in the range of 0.90 to 0.95. Spoilage and the growth of most pathogenic bacteria is retarded because of low water activity, low temperature, and packaging. However, it is contaminated with bacteria of public health significance and poses a hazard to the consumer because it is consumed raw without any cooking. The effectiveness of these hurdles in preventing the growth of Staphylococcus aureus, Bacillus cereus, Salmonella Typhimurium, and Escherichia coli and the efficacy of irradiation treatment in eliminating these bacteria from kwamegi using inoculated pack studies was examined. Radiation sensitivity of S. aureus, B. cereus, Salmonella Typhimurium, and E. coli in kwamegi was investigated. D10-values of these organisms in kwamegi were 590 ± 13.6, 640 ± 14.9, 560 ± 45.4, and 550 ± 8.6 Gy, respectively. The growth of all four test organisms inoculated into these foods during 4 weeks of storage at an ambient winter temperature (ranging from −5°C to +5°C) was recorded. All four pathogens (inoculated at 106 CFU/g) were eliminated by irradiation at 4 kGy. These studies unequivocally demonstrate that irradiation, with a combination of low water activity and low temperature, results in microbiologically safe kwamegi.

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THE ANTIBIOTIC ACTIVITY OF SOIL MICROORGANISMS AS RELATED TO BACTERIAL PLANT PATHOGENS

Canadian Journal of Botany ◽

10.1139/b54-064 ◽

1954 ◽

Vol 32 (5) ◽

pp. 705-735 ◽

Cited By ~ 15

Author(s):

Z. A. Patrick

Keyword(s):

Plant Pathogens ◽

Bacterial Species ◽

High Specificity ◽

Soft Rot ◽

Soil Microflora ◽

Antibiotic Activity ◽

Pathogenic Species ◽

Xanthomonas Species ◽

Test Organisms ◽

Antibiotic Reactions

In an attempted evaluation of the importance of soil antagonisms as a possible factor in the different survival capabilities of some bacterial plant pathogens in the soil environment, a comparison was made of the numbers of antagonists detected when different plant pathogenic species were used as test organisms in determining the "antibiotic potential" of nine "virgin" soils. It was found that there are present among the soil flora a great abundance of microorganisms intrinsically capable of antagonizing most of the bacterial pathogens tested and only for a few species are such antagonists relatively rare. There were great differences in the number of isolates antagonistic to the different pathogenic species, even in the same genus, and there seemed to be a correlation between the numbers of antagonists, as found here, and the capability of a species to maintain itself for long periods in the soil. For the most part the Xanthomonas species appeared to be most sensitive to the antagonistic soil microflora while the soft-rot-causing Erwinia species were most resistant.A comparative study of the antibiotic activity of 120 of the most active antagonistic isolates tested against 28 bacterial plant pathogens showed that each antagonist was characterized by a specific antibacterial spectrum and those antagonists having the most intense antibiotic activity usually inhibited the greatest number of bacterial species. Many antagonists were highly specific, affecting only certain groups or even certain species. The high specificity which characterized some of the antibiotic reactions was used to separate sharply, consistently, and with minimum effort such closely related species as E. carotovora and E. atroseptica or X. corylina and X. juglandis.

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Antibacterial Potential of the Methanol Stem Bark Extract of Stachytarpheta Indica

Asian Journal of Medical Sciences ◽

10.3126/ajms.v4i4.8248 ◽

2013 ◽

Vol 4 (4) ◽

pp. 5-10

Author(s):

Christian Godwin Akuodor ◽

Monday Pius Udia ◽

Charles Emeka Udenze ◽

John Onyemaechi Ogbonna

Keyword(s):

Antimicrobial Agents ◽

Medical Science ◽

Stem Bark ◽

Bark Extract ◽

Significant Activity ◽

E Coli ◽

Diffusion Technique ◽

Shigella Spp ◽

Test Organisms ◽

Stem Bark Extract

Objective: There is increasing need for potent antimicrobial agents to tackle the problem of diseases in man. In view of this, the activities of methanol stem bark extract of Stachytarpheta indica was evaluated against some disease causing microorganisms. Method: The activity of the extract against S. aureus, P.aeruginosa, E. coli, S. typhi and Shigella spp was determined using agar diffusion technique. Results: The methanol stem bark extract demonstrated significant activity against the test organisms. The Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) of the stem bark extract ranged from 12-60 μg/ml. Conclusion: Further isolation of active compound responsible for the antibacterial activity could be the potential sources of new antibacterial agents. Asian Journal of Medical Science, Volume-4 (2013), Pages 5-10 DOI: http://dx.doi.org/10.3126/ajms.v4i4.8248

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Growth of Salmonella and Other Foodborne Pathogens on Inoculated Inshell Pistachios during Simulated Delays between Hulling and Drying

Journal of Food Protection ◽

10.4315/0362-028x.jfp-18-450 ◽

2019 ◽

Vol 82 (5) ◽

pp. 815-825 ◽

Cited By ~ 3

Author(s):

MAHTA MOUSSAVI ◽

VANESSA LIEBERMAN ◽

CHRIS THEOFEL ◽

JAVAD BAROUEI ◽

LINDA J. HARRIS

Keyword(s):

Escherichia Coli ◽

Relative Humidity ◽

Foodborne Pathogens ◽

Lag Time ◽

Escherichia Coli O157 ◽

Contributing Factors ◽

Shell Surface ◽

E Coli ◽

Significant Growth ◽

Lower Maximum

ABSTRACT During harvest, pistachios are hulled, separated in water into floater and sinker streams (in large part on the basis of nut density), and then dried before storage. Higher prevalence and levels of Salmonella were previously observed in floater pistachios, but contributing factors are unclear. To examine the behavior of pathogens on hulled pistachios during simulated drying delays, floater and sinker pistachios collected from commercial processors were inoculated at 1 or 3 log CFU/g with cocktails of Salmonella and in some cases Escherichia coli O157:H7 or Listeria monocytogenes and incubated for up to 30 h at 37°C and 90% relative humidity. Populations were measured by plating onto tryptic soy agar and appropriate selective agars. In most cases, no significant growth (P > 0.05) of Salmonella was observed in the first 3 h after inoculation in hulled floaters and sinkers. Growth of Salmonella was greater on floater pistachios than on corresponding sinkers and on floater pistachios with ≥25% hull adhering to the shell surface than on corresponding floaters with <25% adhering hull. Maximum Salmonella populations (2 to 7 log CFU/g) were ∼2-log higher on floaters than on corresponding sinkers. The growth of E. coli O157:H7 and Salmonella on hulled pistachios was similar, but a longer lag time (approximately 11 h) and significantly lower maximum populations (4 versus 5 to 6 log CFU/g; P < 0.05) were predicted for L. monocytogenes. Significant growth of pathogens on hulled pistachios is possible when delays between hulling and drying are longer than 3 h, and pathogen growth is enhanced in the presence of adhering hull material.

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INFLUENCE OF ORGANIC MATTER ON THE GERMICIDAL EFFICIENCY OF QUATERNARY AMMONIUM AND HYPOCHLORITE COMPOUNDS

Canadian Journal of Research ◽

10.1139/cjr48f-012 ◽

1948 ◽

Vol 26f (2) ◽

pp. 91-104 ◽

Cited By ~ 3

Author(s):

C. K. Johns

Keyword(s):

Staphylococcus Aureus ◽

Organic Matter ◽

Quaternary Ammonium ◽

Tap Water ◽

Skim Milk ◽

Distilled Water ◽

Water Solutions ◽

E Coli ◽

Test Organisms ◽

High Concentrations

Using Staphylococcus aureus and Eschericha coli as test organisms, the influence of various concentrations of skim milk on the germicidal potency of Roccal and of Dalglish hypochlorite solutions was studied. Both germicides retained their activity in the presence of unexpectedly high concentrations of skim milk, especially against S. aureus. Small concentrations frequently showed a slight potentiating effect in both laboratory and plant tests. The effectiveness of the hypochlorite fell off sharply beyond a certain concentration, while that of Roccal declined more gradually. Solutions of Roccal prepared with tap water were decidedly less active against E. coli than those prepared with distilled water. With the hypochlorite, tap water solutions were equally effective. Against S. aureus, a similar difference was noted although to a lesser extent. Added skim milk depressed the germicidal action of tap water solutions of Roccal to a greater extent than for distilled water solutions, while for the hypochlorite the reverse held true.

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Methylkarranjic acid and Pongamol from Derris indica Seeds and their Antibacterial Activity

Dhaka University Journal of Pharmaceutical Sciences ◽

10.3329/dujps.v6i1.337 ◽

1970 ◽

Vol 6 (1) ◽

pp. 9-13 ◽

Cited By ~ 1

Author(s):

M Abdullahil Baki ◽

Golam Sadik ◽

KAM Shahadat Hossain Mondal ◽

M Ashilk Mosaddik ◽

M Mukhlesur Rahman

Keyword(s):

Antibacterial Activity ◽

Phenolic Compounds ◽

Soluble Fraction ◽

Ethanolic Extract ◽

2D Nmr ◽

Shigella Dysenteriae ◽

E Coli ◽

Nmr Data ◽

Test Organisms ◽

Derris Indica

Two phenolic compounds, methylkarranjic (1) acid and pongamol (2), were isolated from the petroleum ether soluble fraction of an ethanolic extract of Derris indica seeds. The structures of these compounds were confirmed by LC-MS and a series of 1D and 2D NMR data. The solvent solvent partionates of the ethanolic extract and compounds (1 and 2) exhibited moderate antibacterial activity against several test organisms. The minimum inhibitory concentrations (MICs) of 1 and 2 were found to be in the range of 32-128 μg/ml against Bacillus megatorium, Streptococcus β-haemolyticus, Shigella dysenteriae and E. coli. Key words: Derris indica; Leguminosae; Methylkarranjic acid; Pongamol; Antibacterial activity Dhaka Univ. J. Pharm. Sci. 6(1): 9-13, 2007 (June) The full text is of this article is available at the Dhaka Univ. J. Pharm. Sci. website

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Bacterial killing in gastric juice – effect of pH and pepsin on Escherichia coli and Helicobacter pylori

Journal of Medical Microbiology ◽

10.1099/jmm.0.46611-0 ◽

2006 ◽

Vol 55 (9) ◽

pp. 1265-1270 ◽

Cited By ~ 59

Author(s):

H. Zhu ◽

C. A. Hart ◽

D. Sales ◽

N. B. Roberts

Keyword(s):

Escherichia Coli ◽

Helicobacter Pylori ◽

Gastric Juice ◽

Bacterial Killing ◽

E Coli ◽

Test Organisms ◽

H Pylori ◽

Ph Range ◽

K 12 ◽

Rough Mutant

The susceptibility of Escherichia coli and Helicobacter pylori to pH and the effect of pepsin-mediated proteolysis were investigated. This was to establish the relative importance of their bacterial killing properties in gastric juice. Solutions in the pH range 1.5–7.4 with or without pig pepsin A were used, together with seven gastric juice samples obtained from patients undergoing routine gastric collection. Escherichia coli C690 (a capsulate strain), E. coli K-12 (a rough mutant) and Helicobacter pylori E5 were selected as the test organisms. Suspensions of bacteria (1×106 E. coli ml−1 and 1×108 H. pylori ml−1) were pre-incubated with test solutions at 37 °C for up to 2 h, and then cultured to establish the effect on subsequent growth. Survival of bacteria was diminished at pHs of less than 3.5, whereas killing required a pH of less than 2.5. Pre-incubation with pig pepsin at 0.5, 1.0 and 2.0 mg ml−1 at pH 3.5 reduced viable counts by 100 % for E. coli 690 and E. coli K-12 after 100 min incubation. With H. pylori, the viable counts decreased to 50 % of the control after 20 min incubation in 1 mg pepsin ml−1 at pH 2.5, 3.0 and 3.5. The gastric juices showed bactericidal activity at pH 3.5, and the rate of killing was juice dependent, with complete death of E. coli 690 occurring between 5 and 40 min post-incubation. Thus, killing of E. coli and H. pylori occurs optimally at pHs of less than 2.5. At pH 3.5, little effect is observed, whereas addition of pepsin alone or in gastric juice causes a marked increase in bacterial susceptibility, suggesting an important role for proteolysis in the killing of bacteria.

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AKTIVITAS ANTIBAKTERI JAMU MADURA SUBUR KANDUNGAN

el–Hayah ◽

10.18860/elha.v5i2.3021 ◽

2015 ◽

Vol 5 (2) ◽

pp. 65

Author(s):

Andik Wijayanto ◽

Romi Abrori

Keyword(s):

Centella Asiatica ◽

Bioactive Compound ◽

Inhibition Zone ◽

Inhibitory Effect ◽

Antibacterial Drug ◽

E Coli ◽

Kaempferia Galanga ◽

Test Organisms ◽

And Staphylococcus Aureus ◽

Paper Disc

Madurese traditional medicine (herbs) Subur Kandungan is a medicine that is widely used and produced in Madura that contains Curcuma zedoaria (Chrism.)Rosc., Kaempferia galanga L., Foeniculum vulgare Mill., and Centella asiatica (L.)Urb. highly favoredby the Indonesian community, especially women to improve reproductive health but have not been tested scientifically and standardization to ensure efficacy and safety. Initial stageis screening bioactive compound and then antibacterial activity assay with paper disc method. Clinical bacterial isolates such as Escherichia coli and Staphylococcus aureus were used as test organisms. The best treatment to inhibit the growth of E. Coli and S. aureusis 70% ethanol at a concentration of extract 1000 mg/ml with inhibition zone respectively 5mm and 6.5mm. Although in crude extract form, Madurese traditional medicine (herbs) Subur Kandungan had inhibitory effect on the growth of the E.coli and S.aureus so this traditional medicine potential as an antibacterial agent. It is recommended that further work be done to identify the specific secondary metabolite compound that responsible for this effect, purify it, and standardize as same as a antibacterial drug.

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